Yokogawa PC-Based MX100 - Manual (Page 42)

2-13
SM MX100-01E
Testing
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2.4.6 Reference Junction Compensation Accuracy
Cautions When Performing This Test
• The test module uses slots number 0 through 4. A dummy input module (MX110 H04
INPUT MODULE or equivalent) is installed into slot 5.
When performing a test using fewer than 5 modules, install the modules into
contiguous slots starting with slot 0, with the dummy input module installed in the last
slot. The dummy input module is installed simulate common installation conditions for
its neighboring module.
Example: when testing 3 modules at once
Dummy
input
module
MX110
H04
INPUT
#2
MX110
H04
INPUT
#3
MX110
H04
INPUT
#1
MX100
Slot 5 Slot 3 Slot 4 Slot 0 Slot 2 Slot 1
Install the EUT modules to test from the right and then the dummy module last.
Use another MX110-UNV-H04 as the dummy.
• Using a calibrated thermocouple (Type-T), confirm that the criteria are met when
factoring in the calibration value.
• Monitor the 0°C standardized temperature tank, confirming that it stays at 0±0.01°C.
If the temperature tank is off, confirm that the difference is within the allowable range.
• When using a zero-controlled device, the tip of the thermocouple floats 5-10 mm off
the bottom. However, that distance varies depending on the model. Please see the
user’s manual.
• Perform the test in a stable environment. If drafts are present, position the equipment
to avoid them.
• Allow the instruments to warm up for at least 30 minutes before performing the test.
Note that you must wait at least 15 minutes after wiring the thermocouple.
• Always use terminal covers.
• If the measured values are questionable, record 50 to 100 data, then make a
determination based on the average or median value.
• The MX110-UNV-H04 modules have a separate RJC for each channel, so the criteria
must be met on each channel (1 through 4).
• Measurement fluctuation errors must be prevented as much as possible by adopting
the following setting conditions.
Measurement interval: 100 ms; Filter: 0
• Confirm that the fluctuation among 50 data meets the criterion.
Criterion: 0.2°C or less
If the test results do not meet the criteria, reconfirm the items above.
Procedure
Perform measurement using the Type-T thermocouple at 0°C.
Confirm that the measured values meet the criterion.
Criterion: 0±0.4°C or less
Causes of Failure
If the test results do not meet the criteria, the following causes may apply.
• Faulty RJC board connection
• Defective RJC board (B8720TH)
2.4 Tests of the 4-CH, High-Speed Universal Input Module (MX110-UNV-H04)